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newtyping [2017/04/14 09:44]
christian [Implementation]
newtyping [2017/10/12 14:09]
christian [Implementation]
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 ====== PDF types in PDFtalk ====== ====== PDF types in PDFtalk ======
  
-A PDF consists of a network of objects which are connected through attributes of dictionaries or arrays. The PDF specifiction defines restrictions for which objects can be held by an attribute.+A PDF consists of a network of objects which are connected through their attributes. The PDF specifiction defines restrictions for what objects can be held by an attribute.
  
 The restrictions specify The restrictions specify
-  * which kind of object - its PDF type - including forms like ''Array of aType'' or ''Dictionary of aType''.+  * which type of object including forms like ''Array of aType'' or ''Dictionary of aType''.
   * whether it is or can be indirectly held by a reference   * whether it is or can be indirectly held by a reference
   * whether it is required or optional.   * whether it is required or optional.
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 When PDF objects are read from a file, the are syntactically differentiated as primitive object (Number, String, Name, Boolean etc.) or as Array, Dictionary or Stream. These are raw unspecified objects. When PDF objects are read from a file, the are syntactically differentiated as primitive object (Number, String, Name, Boolean etc.) or as Array, Dictionary or Stream. These are raw unspecified objects.
  
-When such an object is assigned to an attribute of a Dictionary or Array with ''#at:put:'', the types are checked and the raw object is specialized to a fitting subclass. The process can be explained best with a sequence diagram:+When such an object is assigned to an attribute of a Dictionary or Array with ''at:put:'', the types are checked and the raw object is specialized to a fitting subclass. The process can be explained best with a sequence diagram:
  
 {{:pdf:2017-04-13_typing_sequence.jpg?direct&200|}} {{:pdf:2017-04-13_typing_sequence.jpg?direct&200|}}
  • newtyping.txt
  • Last modified: 2017/10/12 14:09
  • by christian